Keithley 2701, User Manual

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Model 2701 User’s Manual Remote Operations 10-25
Single command messages
The above command structure has three levels. The first level is made up of the root
command (STATus) and serves as a path. The second level is made up of another path
(:OPERation) and a command (:PRESet). The third path is made up of one command for
the :OPERation path. The three commands in this structure can be executed by sending
three separate program messages as follows:
stat:oper:enab <NRf>
stat:oper:enab?
stat:pres
In each of the above program messages, the path pointer starts at the root command (stat)
and moves down the command levels until the command is executed.
Multiple command messages
You can send multiple command messages in the same program message as long as they
are separated by semicolons (;). The following is an example showing two commands in
one program message:
stat:oper; stat:oper:enab <NRf>
When the above is sent, the first command word is recognized as the root command (stat).
When the next colon is detected, the path pointer moves down to the next command level
and executes the command. When the path pointer sees the colon after the semicolon (;), it
resets back to the root level and starts over.
Commands that are on the same command level can be executed without having to retype
the entire command path. Example:
stat:oper:enab <NRf>; enab?
After the first command (:enab) is executed, the path pointer is at the third command level
in the structure. Since :enab? is also on the third level, it can be typed in without repeating
the entire path name. Notice that the leading colon for :enab? is not included in the
program message. If a colon were included, the path pointer would reset to the root level
and expect a root command. Since :enab? is not a root command, an error would occur.
2701-900-01.book Page 25 Wednesday, August 3, 2011 9:43 AM